The human race has generated increasing volumes of waste per capita since prehistory. Archeology is mainly excavation of waste dumps. The earliest known settlements are buried in their own waste.
The current generation of waste, leaving aside hazardous, toxic, radioactive and industrial waste.. pollution and other effects, is already well past the crisis level. A major problem is disposal of solid waste at the municipal level. This solid waste includes residential, institutional, commercial and industrial solid waste.
The major component of waste in North America is residential solid waste. At present municipal solid waste (solid waste directly disposed of by municipal authorities) is mostly residential solid waste.
The volume of residential solid waste has grown with increasing population, increasing urbanization, and increasing consumption. The answer to solid waste disposal has been municipal waste disposal sites evolving into sanitary landfills. At present residential solid waste is being generated at a level approximating 1 ton (2,000 lbs per capita, annually, in North America, or approximately 2 cubic meters, (70 cubic feet). In most urban environments solid waste disposal is already a major problem.
Elsewhere even though solid waste production is less per capita, the population is generally denser, consequently municipal solid waste disposal is similarly a major problem.
The growth of world population and urbanization, (estimated to reach 10 billion and 50% of population, respectively by 2050) will exacerbate the solid waste disposal problem. The inevitable proliferation of conurbations of 5 million plus, will propel it into crisis. Conurbations of such size have already lost control of their solid waste disposal.
Even were sufficient land available for sanitary landfills, which is not the case, even in relatively unpopulated North America, there are already environmental problems, which are inevitably escalating to environmental crisis.
In conventional current landfill, the soil is excavated, typically to a lesser depth than the permanent groundwater table. A compacted layer or stratum of soil forms the bottom of the landfill, which is covered with a impermeable plastic liner, or a geotextile, to allow contaminated liquid leachates access to removal points rather than escaping into the groundwater. Even when geotextiles are used excavation is not generally permitted below 5 feet (1.5 meters) above the permanent groundwater table. Every form of solid waste is then deposited to a compacted "lift" typically 6 to 10 feet deep forming a horizontal cell. A shallow stratum of compacted soil.. typically 1 to 3 feet deep is then deposited on the waste materials and the process repeated. The resulting mass of landfill generally rises above original ground level, in some cases up to 150 feet high, forming a "mountain" of waste. Some of these are gigantic, the Fresh Kills site adjacent New York City, being large enough to be visible from the Moon. There are thousands of similar mountains of waste throughout North America.
In practice the landfills are sources of pollution and contamination. Older landfills may not have an impermeable liner, or leachate removal system, and their leachates contaminate the soil and groundwater. Newer landfills are not supposed to allow leachates to escape, however geotextiles, liners and geomembranes are nearly always ruptured to some extent by hydrostatic pressure, man made events or natural phenomena. This allows leachate to contaminate the groundwater to an increasing degree. The air is contaminated downwind of the landfills for considerable distances, similarly neighboring soil and water are contaminated, by airborne and waterborne waste, surface runoff and subsurface groundwater migration. A landfill in use is often infested with birds, rodents and litter. Besides this the landfill site itself is contaminated for at least several decades, and generates quantities of fermentation gas, mainly methane and carbon dioxide. As the contents of landfills are variable and unknown it is difficult to take counter measures to prevent pollution and contamination of the local environment. It is also difficult to predict the long term effects of such contamination and pollution. Consequently the interim use of former landfill sites is restricted to parks, recreation areas, etc., for many years after the landfill decommissioning. This is a gross misuse of valuable natural resources.